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Biomedical subjects

B Boyer

Publications and source records attributed to B Boyer.

At least 109 records · Page 6Linked to original sources
PubMed1987

The epidemiological importance of intraindividual changes in objective pulmonary responses.

Debate continues about what constitutes significant and meaningful change in health status of individuals and populations. More importantly, the basic biological and medical criteria that are used for clinical and environmental judgments require further discussion and clarification. What proportion of loss of cardio-pulmonary function, overt disability, or mortality is sufficient to determine an "adverse health effect"? Health-oriented individuals, including researchers and clinicians, may choose to adhere to different criteria than other professional groups (e.g., legal, social). It is proposed in this paper that criteria for defining adverse health effects should represent clinically meaningful, as distinct from only statistically significant, responses. These include pulmonary function test results that indicate obstructive or restrictive diseases, and electrocardiogram results indicating coronary artery disease. Intraindividual changes that predict a meaningful medical change would be included; these changes should meet specific requirements in terms of what constitute normal vs. abnormal ranges of variation. Further, the proportion of the population defined to be impaired should be considered. These issues are the focus of this paper.

Adult↗
PubMed1987

Development of class I-specific helper-inducer T-cell clone.

A unique alloreactive human helper-inducer T-cell clone which reacts with the class I HLA antigen was characterized. The clone was derived from a mixed lymphocyte culture between cells from a HLA-A2-; B35,w51; Bw4,Bw6; Cw4,-; DR1,4; DQw1,-; DRw53 responder and a HLA-A2,3; B7,14; Bw6; Cw8,-; DR7,-; DQw2,w3; DRw52 stimulator. When screened against a panel of stimulator cells, this clone was found to have a specificity towards a stimulator HLA-B14 and consisted entirely of Leu-4, Leu-3, and 4B4 positive T cells, which is a T helper-inducer phenotype. Using monoclonal antibodies directed towards various monomorphic class I and II HLA epitopes in an inhibition experiment, it was found that both monoclonal antibodies w6/32 and 4E (recognizing class I monomorphic and HLA-B epitopes, respectively) inhibited proliferation. However, monoclonal antibodies BBm.1 and L227 (directed against beta 2-microglobulin and Ia-like molecule, respectively) had no inhibitory effect. Functional evaluation of this clone demonstrated helper activity on the proliferation of MLC response. The helper-induction effect on MLC cultures remained intact following irradiation of the clone for either 500 or 2000 rad suggesting that helper function of the clone was radiation resistant. The helper activity of this clone was MHC nonrestricted since it enhanced proliferation of the original responder and stimulator MLC as well as third and fourth party individuals. By CTLL cell line proliferation assay, this clone was found to release IL-2. When assayed (day 1 to 7) for class II HLA products expression following stimulation, HLA-DRw53 was consistently expressed by the clone. However, HLA-DR1, DQw1 were found to be expressed simultaneously on day 2 through day 7 and HLA-DR4, DQw3 on day 2 and 3. These data demonstrate, for the first time, the generation of a class I specific helper-inducer T-cell clone in MLC response.

Antibodies, Monoclonal↗
PubMed1987

[Non-gynecologic fluid images of pelvis. Ultrasonic study].

From a series of 6,573 echographic surveys of pelvis in male and female, the authors point out 789 liquid images among them 82 are non gynecologic lesions. A statistical study of the different observed etiologies is proposed and compared with those of the literature. The main cases observed are gathered under several items: abscess, hematomas, urinary, digestive and vascular images and studied semiologically. The discussion points out the low frequency in opposition to the etiological diversity of this type of image and precise the diagnostic procedures rules which include other imaging methods especially computed tomography.

Abscess↗
PubMed1987

[Polysplenia with duplication of the inferior vena cava. Apropos of a case].

A case of polysplenia fortuitously discovered in an adult by sonography, then studied by computed tomography and inferior vena cavography, is reported. In the absence of cardiac anomalies, the different elements of the syndrome are discussed: multiple spleens, abdominal heterotaxia and vascular malformations. The duplication of the inferior vena cava is exceptional in this disease. Its original characteristic is shown by the cavography and brought to its embryologic origin.

Aged↗
PubMed1986

A quantitative dot immunobinding assay for human HLA class II antigens using nitrocellulose membrane filters.

A quantitative method for the evaluation of human HLA-DR antigen expression has been developed. Cell membrane proteins were solubilized in Nonidet P-40 or deoxycholic acid detergent and diluted in a Triton X-100 containing sample buffer. The samples were subsequently spotted on a nitrocellulose membrane filter and fixed by immersion in isopropyl alcohol-acetic acid solution. The membrane was saturated in a 5% BSA blocking buffer and sequentially incubated with specific monoclonal anti-HLA-DR antibody, and 125I-labelled protein A. Each spot was then assayed for radioactivity in a gamma scintillation counter. Immunoadsorbant purified HLA-DR antigen was used to standardize the method and a reference dosage curve was established with serial dilutions of the purified HLA-DR antigen. The method permitted the detection of HLA-DR antigens with reproducibility in the ng range, in cellular extracts, physiological and pathological fluids, and in fractions eluted from affinity columns.

Cell Line↗
PubMed1986

Control of erythroid differentiation: asynchronous expression of the anion transporter and the peripheral components of the membrane skeleton in AEV- and S13-transformed cells.

Chicken erythroblasts transformed with avian erythroblastosis virus or S13 virus provide suitable model systems with which to analyze the maturation of immature erythroblasts into erythrocytes. The transformed cells are blocked in differentiation at around the colony-forming unit-erythroid stage of development but can be induced to differentiate in vitro. Analysis of the expression and assembly of components of the membrane skeleton indicates that these cells simultaneously synthesize alpha-spectrin, beta-spectrin, ankyrin, and protein 4.1 at levels that are comparable to those of mature erythroblasts. However, they do not express any detectable amounts of anion transporter. The peripheral membrane skeleton components assemble transiently and are subsequently rapidly catabolized, resulting in 20-40-fold lower steady-state levels than are found in maturing erythrocytes. Upon spontaneous or chemically induced terminal differentiation of these cells expression of the anion transporter is initiated with a concommitant increase in the steady-state levels of the peripheral membrane-skeletal components. These results suggest that during erythropoiesis, expression of the peripheral components of the membrane skeleton is initiated earlier than that of the anion transporter. Furthermore, they point a key role for the anion transporter in conferring long-term stability to the assembled erythroid membrane skeleton during terminal differentiation.

Alpharetrovirus↗
PubMed1984

Heterogeneity of plasminogen activator expression in various Moloney virus-induced tumor cell lines. Lack of correlation with tumor growth and cell phenotype.

The aberrant expression of a plasminogen activator (PA) by Moloney virus (MuLV)-transformed mouse lymphocytes and its relation to cell phenotype and tumor growth have been studied. Nine cultured cell lines were established from neoplastic splenic and thymic tissues obtained from B10 congeneic mice inoculated with MuLV and killed when overtly leukemic. Cell surface markers were assayed by microcytotoxicity tests, the concentration of MuLV p30 and group-specific MuLV gp 70 was determined by radioimmunoassays and the expression of PA activity was assessed in a fibrin-agar plate method. PA activity of 24 h serum-free culture supernatant, intact cells or cell lysates (2 X 10(5) cells/ml) was expressed in International Units by reference to a urokinase standard curve. Tumor extension and cell morphology were investigated by histologic and cytomorphologic analysis. In all cases the cell lines were derived from T cells. PA activity is not expressed by normal lymphocytes, but variations in PA expression were observed in the transformed cells. Five out of nine transformed cell lines showed PA activity with a range of 1.3 to 9.9 IU/ml. No PA activity could be detected in the other cell lines. No correlation was found between PA expression and the cell-surface-expressed phenotype, neither was there any correlation between the PA content, the cytopathological features and the degree and type of organ infiltration. This lack of correlation indicates that there is no relation between PA activity and the expression of the transformed phenotype, and that the presence of PA activity seems to be irrelevant to the tumorigenic capacities of the transformed cell lines.

Animals↗
PubMed1983

Syngeneic anti-idiotypes against monoclonal anti-HLA-DR antibodies: characterization of recurrent idiotopes.

Monoclonal anti-HLA-DR antibody (anti-DR mAb) reactivity was investigated at the idiotypic level; three syngeneic anti-idiotype (Id) sera were raised against three monomorphic anti-DR mAb (206, BM 50, and D 1.12). The syngeneic anti-Id responses exhibited some differences in their intensity and the idiotypic determinants recognized by the three anti-Id sera were localized, at least in part, on the antigen combining site of the respective anti-DR mAb. Idiotype analysis of 24 anti-DR mAb was performed with these anti-Id sera by Id-binding inhibition assays. Idiotypic cross-reactivity was demonstrated for 12 out of the 24 anti-DR mAb, indicating a large degree of idiotypic recurrence. Analysis of the cross-inhibition patterns led us to define at least five sets of recurrent idiotopes: one set cross-reacting with anti-206 Id, the second with both anti-BM 50 and anti-D 1.12 Id, the third with anti-BM 50 Id only, the fourth with anti-D 1.12 Id only, and a fifth set was shared by D 1.12 and NE 4. Eleven monomorphic anti-DR mAb and one polymorphic anti-DR 3 mAb (16.23) did not cross-react with the three anti-Id sera. These results suggest that the mouse antibody response to monomorphic determinants on human Ia antigens is based on a limited number of recurrent idiotopes. In two cases, recurrent idiotopes could be related to a similar anti-DR mAb fine specificity. These anti-Id provide useful reagents to classify and compare anti-DR mAb.

Animals↗
PubMed1982

Genetic control of sensitivity to moloney leukemia virus in mice. VI. Involvement of virus-specific T helper cells collaborating with B cells.

T cell responses to Moloney virus involve cytolytic and helper lymphocytes. In contrast to specific cytolytic T lymphocytes, few studies have been devoted to the characteristics of helper T cells for antibody production. The present experiments describe an assay for Moloney virus-specific help for B cells using dinitrophenylated virus. This method, using the Moloney virus as a carrier in a hapten-carrier system, allows to definition of the specific helper function of antibody responses. T helper cells were induced in murine sarcoma virus or inactivated Moloney murine leukemia virus-primed spleens or lymph nodes. T helper function was due to Thy-1.2, Lyt-1+2- cells and was macrophage-dependent. It was stimulated by whole virus of Moloney gp71 envelope protein but not Moloney p30 internal protein. Cross-reactive stimuli were obtained with other dinitrophenylated type C viruses. High and low responses were correlated respectively with resistance and susceptibility to Moloney leukemia virus. Cultures of helper T cells with preserved activity have been established and maintained for one month.

Animals↗
PubMed1981

Calcified portal vein thromboemboli in infants: radiography and ultrasonography.

Calcified portal vein thromboemboli (CPVT) in six neonates are reported. Three of the infants had multiple chromosomal abnormalities. Ultrasonography was performed in one patient to confirm the intrahepatic location of the calcification. CPVT, which are usually incidental observations on abdominal radiographs in neonates, should be considered in the differential diagnosis of calcifications limited to the hepatic area. These lesions are usually peripheral, and seem to be associated with multiple anomalies in infants. Ultrasonography is useful in demonstrating the intrahepatic and peripheral location of these calcifications.

Abnormalities, Multiple↗
PubMed1981

Incidence and phenotypic heterogeneity of Moloney virus-induced leukemias: a multigenic control.

The incidence of leukemias was established in mice of different inbred strains inoculated with Moloney leukemia virus (M-MuLV), and a complex genetic control was found. To characterize the different steps of the host-virus relationship further, the degree of viremia, the appearance of leukemia, organ involvement, and the surface phenotype of leukemic cells were studied in individual mice. The results demonstrate that: a) The viremia was controlled by H-2 and non-H-2 genes. Three H-2 genes located in the I and D or T region of the MHC behave like immune-response genes controlling the specific antiviral immune response. Other gene(s) mapped outside the complex also affected the virus production. Both sets of genes influenced leukemia incidence, since leukemias were observed only in highly viremic strains. b) Additional non-H-2 genes, which were not involved in viremia control, were determinants in the induction of malignancies because some sensitive strains do not become leukemic despite high levels of viremia. c) The anatomical type of Moloney virus-induced leukemias varied according to the non-H-2 background. Most of the leukemias arising in B10 congeneic mice involved the thymus and were frequently limited to this organ, whereas BALB mice preferentially developed splenic leukemias. d) In a given inbred strain, the leukemias arising in different animals frequently expressed different phenotypes. It can be concluded that Moloney virus-induced leukemia is a multistep process, viral production being necessary but not sufficient in and of itself to induce a malignant transformation.

Animals↗
PubMed1980

Genetic control of sensitivity to Moloney leukemia virus in mice. III. The three H-2 linked Rmv genes are immune response genes controlling the antiviral antibody response.

It has been shown previously that three different H-2-associated genes control the resistance to viremia and leukemia in Moloney virus-infected mice: Rmv. 1, mapping to the I-A or less probably K regions; Rmv. 2, mapping to the I-C, S or G regions and Rmv. 3, mapping to the D or T regions. Experiments have been performed to determine the role of these genes in the control of the antibody responses directed against Moloney murine leukemia virus (M. MuLV) virions and/or leukemic cells. The inoculation of infectious M.MuLV failed to provide conclusive responses due to unequal replication of the virus in different inbred strains resulting in variable antigenic stimulations and/or in vivo antibody absorptions. The use of inactivated M.MuLV as antigen allowed to avoid these problems. It showed that (2) the IgG-specific antiM.MuLV response is controlled by H-2 linked genes, (b) a clear correlation exists between high or low-responder phenotypes and the resistance or susceptibility to M.MuLV infection and (c) all three Rmv genes behave like immune response genes. These results were not surprising for Rmv. 1 and Rmv. 2 which map in the I region of the major histocompatibility complex. It was more puzzling for Rmv. 3. Further experiments are necessary to determine the exact mechanism by which this gene controls the immune response.

Animals↗
PubMed1979

Visual compatibility of 30 additives with a parenteral nutrient solution.

The visual compatibility of 30 drug additives with total parenteral nutrient (TPN) solutions (4.25% amino acids, 25% dextrose injection) was studied. For each drug additive, three TPN solutions were mixed; two were stored for 22 hours at 4 C then allowed to equilibrate to room temperature for two hours. Two 25-ml samples from each TPN solution were examined immediately or after 25 hours for visual appearance, particulate matter levels and pH. A microscope was used to count and measure particles filtered from samples on a 0.8-micrometer filter. Only the TPN solutions containing amphotericin B showed any visual discoloration or precipitation. All amphotericin B samples and the 25-hour ampicillin sodium samples exceeded USP particulate matter specifications. Individual particulate matter levels of the other TPN solutions varied but met USP specifications. With the exception of tetracycline hydrochloride, which dropped the TPN solution's pH 0.9 units, the additives had little effect on pH of the TPN solutions (pH 6.45). Amphotericin B and ampicillin sodium were considered visually incompatible with TPN solutions. All other drug additives tested were visually compatible with TPN solutions.

Drug Combinations↗